One of the major challenges in television broadcasting lies in sharing content such as an audio-visual content and associated metadata with remotely located individual viewers. The broadcasted content is first compressed and then broadcasted from a television broadcasting station that may then be received by antennas employed by individual users. Such stations transmit multiple audio-visual contents broadcasted by various broadcasting channels on the television sets located worldwide that displays the contents on TV display screen.
With the enhancement of technology related to content broadcasting methods and ubiquitous presence of television sets across the world and specifically in developing and under developed countries, there has been an enhancement in utilization of television for interactive applications such as online gaming, distance-learning and online chatting etc. These applications supported by the television broadcast have resulted in the concept of “Interactive TV”.
The significance of “Interactive TV” has been accepted by all the sections of the society including the service providers, the customers and the government agencies. Therefore, there was a need in the art to enable a television broadcasting system that supports interactive applications as desired by the consumer at his or her home using the television as a medium for accessing various interactive applications.
However, as can be observed, the present broadcasting scenario is limited to transmit conventional audio, video, PSI and SI data only. Further, the data type associated with interactive applications may not be enabled to transfer using existing broadcasting infrastructure. Moreover, if the data type is other than the conventional audio, video, PSI and SI data then the data of such data type may not be transmitted using the existing broadcasting infrastructure. Hence, there is a need to enable system for transferring any other data type along with the conventional data type supported for transmission.
In the background art, a PCM Adaptor is known to enable embedding of raw audio data into a video frame. Also, there are systems known in the art embedding teletext and closed captions in the lines of vertical blanking interval (VBI) as disclosed in the CEA-608 standard. Further, there exist various systems to transmit digitally encoded bits in the VBI (vertical blanking interval) wherein, 7175 bits per second per line can be transmitted. However, there is a limit for the number of VBI lines which is of the order of 20-40 lines. Moreover, at the receiver end, for decoding the embedded data of different types using the existing systems requires the support for specialized hardware devices. The VBI lines contain teletext, closed captions and electronic program guide (EPG). Hence, there is a limit for number of free lines available to send new type of data.
Moreover, along with the audio-visual content certain metadata is also required to be embedded in the transmitted analog signal. The solutions provided by the existing technology are unable to provide a method for embedding the related metadata in a transmitted signal that is robust enough to sustain video compression and digital to analog conversions in the digital TV broadcast. Further, multiplexing multiple tutorials along with audio is not possible in a single analog TV channel. The Indian Patent Application no. 2422/MUM/2011 describes a solution for embedding metadata such as tutorial related Question-Answer and other related data in the analog video signal. The prior filed Indian Patent Application also describes transmitting tutorial information and associated metadata of the tutorials and the EPG in a single analog video channel along with the normal video. All these metadata are multiplexed as part of the pixels in the video frame.
However, in addition to there is a need for a method for embedding metadata specifically multiple encoded digital audio channels, question-answer (QA) and other related data as part of the analog video. The need is to make the metadata embedding method robust enough to sustain video compression and digital to analog conversions in the digital TV broadcast.
In view of the above lacunae observed in the background art, there is a long-felt need for a method for multiplexing several tutorials in a single analog channel by multiplexing multiple video channels in a single video channel and multiplexing and embedding multiple encoded digital audio and other related data, termed as metadata as part of the analog video. Further requirement is to make the metadata embedding method robust enough to sustain video compression and digital to analog conversions in the digital TV broadcast and to provide a superior user experience.